Elevating Unit; Refrigerant Line Set Selection; Replacing Existing Systems; Line Set Length And Fitting Losses - Rheem A17 Series Installation Instructions Manual

4.0 INSTALLATION

4.3.3 Elevating Unit

WARNING:
its elevating stand in order to prevent tipping. Failure to
do so may result in severe personal injury or death.
If elevating the unit, either on a flat roof or on a slab,
observe the following guidelines.
If elevating a unit on a flat roof, use 4" x 4"
[10.2 cm x 10.2 cm] or equivalent stringers positioned
to distribute unit weight evenly and prevent noise and
vibration.

4.4 Refrigerant Line Set Selection

4.4.1 Replacing Existing Systems

To prevent failure of a new unit, the existing line set
must be correctly sized for the new unit and must
be cleaned or replaced. Care must be taken so
the expansion device is not plugged. For new and
replacement units, a liquid line filter drier must be
installed and the line set must be properly sized.
Test the oil for acid. If it tests positive for acid, a
suction line filter drier is mandatory.

4.4.2 Line Set Length and Fitting Losses

Refrigerant tubing is measured in terms of actual
length and equivalent length. Actual length is used
for refrigerant charge applications. Equivalent
length takes into account pressure losses from
10
Secure an elevated unit and
Table 1
NOTICE:
DO NOT block drain openings
on bottom of unit.
If unit must be elevated, secure unit and elevating
stand such that unit and/or stand will not tip over
or fall off. Keep in mind that someone may try to
climb on unit.
ELEVATE ABOVE
ANTICIPATE HIGH
SNOW FALL
DO NOT BLOCK
OPENINGS
IN BASE PAN
ST-A1226-03-00
IMPORTANT:
R-22 unit with an R-410A unit, either replace
the line set or ensure that residual mineral oil is
drained from existing lines including oil trapped in
low spots
tubing length, fittings, vertical separation, accesso-
ries, and filter driers. The table below references
commonly used equivalent lengths.
BASE PAD
(CONCRETE OR OTHER SUITABLE
MATERIAL)
When replacing an